JavaScript image compressor. Uses the Browser's native canvas.toBlob API to do the compression work, which means it is lossy compression. General use this to precompress a client image file before upload it.

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dist/
├── compressor.js        (UMD)
├── compressor.min.js    (UMD, compressed)
├── compressor.common.js (CommonJS, default)
└── compressor.esm.js    (ES Module)

npm install compressorjs

new Compressor(file[, options])

file

• Type: File or Blob

The target image file for compressing.

options

• Type: Object
• Optional

The options for compressing. Check out the available options.

<input type="file" id="file" accept="image/*">

import axios from 'axios';
import Compressor from 'compressorjs';

document.getElementById('file').addEventListener('change', (e) => {
  const file = e.target.files[0];

  if (!file) {
    return;
  }

  new Compressor(file, {
    quality: 0.6,
    success(result) {
      const formData = new FormData();

      // The third parameter is required for server
      formData.append('file', result, result.name);

      // Send the compressed image file to server with XMLHttpRequest.
      axios.post('/path/to/upload', formData).then(() => {
        console.log('Upload success');
      });
    },
    error(err) {
      console.log(err.message);
    },
  });
});

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You may set compressor options with new Compressor(file, options). If you want to change the global default options, You may use Compressor.setDefaults(options).

• Type: boolean
• Default: true

Indicates if output the original image instead of the compressed one when the size of the compressed image is greater than the original one's, except the following cases:

• The mimeType option is set and its value is different from the mime type of the image.
• The width option is set and its value is greater than the natural width of the image.
• The height option is set and its value is greater than the natural height of the image.
• The minWidth option is set and its value is greater than the natural width of the image.
• The minHeight option is set and its value is greater than the natural height of the image.

• Type: boolean
• Default: true

Indicates if read the image's Exif Orientation value (JPEG image only), and then rotate or flip the image automatically with the value.

Notes:

• Don't trust this all the time as some JPEG images have incorrect (not standard) Orientation values.
• If the size of target image is too large (e.g., greater than 10 MB), you should disable this option to avoid out-of-memory crash.

• Type: number
• Default: Infinity

The max width of the output image. The value should be greater than 0.

Avoid to get a blank output image, you might need to set the maxWidth and maxHeight options to limited numbers, because of the size limits of a canvas element, recommend to use 4096 or lesser.

• Type: number
• Default: Infinity

The max height of the output image. The value should be greater than 0.

• Type: number
• Default: 0

The min width of the output image. The value should be greater than 0 and should not be greater than the maxWidth.

• Type: number
• Default: 0

The min height of the output image. The value should be greater than 0 and should not be greater than the maxHeight.

• Type: number
• Default: undefined

The width of the output image. If not specified, the natural width of the original image will be used, or if the height option is set, the width will be computed automatically by the natural aspect ratio.

• Type: number
• Default: undefined

The height of the output image. If not specified, the natural height of the original image will be used, or if the width option is set, the height will be computed automatically by the natural aspect ratio.

• Type: number
• Default: 0.8

The quality of the output image. It must be a number between 0 and 1. Be careful to use 1 as it may make the size of the output image become larger. Check out canvas.toBlob for more detail.

Note: This option only available for image/jpeg and image/webp images.

Examples:

• Type: string
• Default: 'auto'

The mime type of the output image. By default, the original mime type of the source image file will be used.

• Type: number
• Default: 5000000 (5 MB)

PNG files over this value will be converted to JPEGs. To disable this, just set the value to Infinity.

Examples:

• Type: Function
• Default: null
• Parameters:
  • context: The 2d rendering context of the canvas.
  • canvas: The canvas for compression.

The hook function to execute before draw the image into the canvas for compression.

new Compressor(file, {
  beforeDraw(context, canvas) {
    context.fillStyle = '#fff';
    context.fillRect(0, 0, canvas.width, canvas.height);
    context.filter = 'grayscale(100%)';
  },
});

• Type: Function
• Default: null
• Parameters:
  • context: The 2d rendering context of the canvas.
  • canvas: The canvas for compression.

The hook function to execute after drew the image into the canvas for compression.

new Compressor(file, {
  drew(context, canvas) {
    context.fillStyle = '#fff';
    context.font = '2rem serif';
    context.fillText('watermark', 20, canvas.height - 20);
  },
});

• Type: Function
• Default: null
• Parameters:
  • result: The compressed image (a File (read only) or Blob object).

The hook function to execute when success to compress the image.

• Type: Function
• Default: null
• Parameters:
  • err: The compression error (an Error object).

The hook function to execute when fail to compress the image.

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Abort the compression process.

const compressor = new Compressor(file);

// Do something...
compressor.abort();

If you have to use other compressor with the same namespace, just call the Compressor.noConflict static method to revert to it.

<script src="other-compressor.js"></script>
<script src="compressor.js"></script>
<script>
  Compressor.noConflict();
  // Code that uses other `Compressor` can follow here.
</script>

• Chrome (latest)
• Firefox (latest)
• Safari (latest)
• Opera (latest)
• Edge (latest)
• Internet Explorer 10+

Please read through our contributing guidelines.

Maintained under the Semantic Versioning guidelines.

MIT © Chen Fengyuan

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